National Semiconductor ADC0820 Manuals

ADC0820 8-Bit High Speed µP Compatible A/D Converter with Track/Hold Function General Description By using a half-flash conversion technique, the 8-bit ADC0820 CMOS A/D offers a 1.5 µs conversion time and dissipates only 75 mW of power. The half-flash technique consists of 32 comparators, a most significant 4-bit ADC and a least significant 4-bit ADC. The input to the ADC0820 is tracked and held by the input sampling circuitry eliminating the need for an external sample-and-hold for signals moving at less than 100 mV/µs. For ease of interface to microprocessors, the ADC0820 has been designed to appear as a memory location or I/O port without the need for external interfacing logic. Key Specifications n Resolution 8 Bits n Conversion Time 2.5 µs Max (RD Mode) 1.5 µs Max (WR-RD Mode) n Low Power 75 mW Max n Total Unadjusted Error ±1⁄2 LSB and ± 1 LSB Features n Built-in track-and-hold function n No missing codes n No external clocking n Single supply — 5 VDC n Easy interface to all microprocessors, or operates stand-alone n Latched TRI-STATE® output n Logic inputs and outputs meet both MOS and T2L voltage level specifications n Operates ratiometrically or with any reference value equal to or less than VCC n 0V to 5V analog input voltage range with single 5V supply n No zero or full-scale adjust required n Overflow output available for cascading n 0.3" standard width 20-pin DIP n 20-pin molded chip carrier package n 20-pin small outline package n 20-pin shrink small outline package (SSOP) Connection and Functional Diagrams TRI-STATE® is a registered trademark of National Semiconductor Corporation. Dual-In-Line, Small Outline and SSOP Packages DS005501-1 Top View Molded Chip Carrier Package DS005501-33 June 1999 ADC0820 8-Bit High Speed µP Compatible A/D Converter with Track/Hold Function © 1999 National Semiconductor Corporation DS005501 www.national.com